Typical of known passive pacing tip electrodes currently in use is a design which comprises four separate components, namely, an electrode, a weld electrode, a steroid plug, and a tine. The assembly of these components has always been a challenging one because of their very small size. First, the steroid plug is inserted into the back end of the tip electrode. Next, the weld electrode is laser welded to the back end of the tip electrode containing the steroid plug. Finally, the tine is installed onto the welded tip subassembly.
The prior art contains numerous examples of tip electrode constructions which are intended to be simplified by the present invention. In this regard, FIGS. 4 and 5 of U.S. Pat. No. 4,711,251, to Stokes, discloses an implantable lead having tines and a plug-like structure to mount a drug to be dispensed. The use of plugs, apertures, and the like within a tined lead are also typically found in U.S. Pat. Nos. 5,496,360, to Hoffmann et al.; 4,819,662, to Heil, Jr. et al.; 4,606,118, to Cannon et al.; and 4,577,642 and 4,506,680, to Stokes. Also of interest are positive fixation designs with drug elution capabilities which are disclosed in U.S. Pat. Nos. 5,003,992, to Holleman et al.; 5,002,067 and 4,953,564, to Berthelsen et al.; and 4,819,661, to Heil, Jr. et al.
It was with knowledge of the foregoing state of the technology that the present invention has been conceived and is now reduced to practice.